A. D. Neklyudov

Properties and uses of protein hydrolysates (Review)

Properties of protein hydrolysates and possible uses of these substances in research and various branches of industry are considered. The main problem discussed in this paper is the relationship between the degree of protein conversion and characteristics (structural-functional and physicochemical) of hydrolysates.

Aerobic processing of organic waste into composts

The current achievements in the field of aerobic waste processing into composts are reviewed, with an emphasis on amelioration of the environment and targeted use for intensification of agriculture. The methods for obtaining microbiological transformation products of household, agricultural, and industrial waste and their characteristics are analyzed.

Biochemical Processing of Fats and Oils As a Means of Obtaining Lipid Products with Improved Biological and Physicochemical Properties: A Review

Recent advances in the improvement of biological and physicochemical characteristics of lipids are reviewed, with emphasis on products of biochemical processing of natural (animal or plant) fats and oils. Possible uses of these new lipid products include their use in food and forage industries, as well as in the production of new medicines and in biotechnology. Specific features of biochemical transformations of lipids (hydrolysis, esterification, and reesterification) in the presence of water-soluble and immobilized lipases of animal, plant, and microbial origin are scrutinized.

Collagen Fractions Obtained by Water–Salt Extraction from Raw Materials of Animal Origin

Collagen fractions have been isolated by water–salt extraction from raw materials of animal origin (various tendon types or subcutaneous tissues of cattle or porcine skin). Collagen fractions with maximum capacity for water and fat retention were isolated with high efficiency by water–salt solutions containing 1–10% sodium chloride at temperatures below 50°C. The values of the effective constant of extraction rate (min–1) at pH 6.5, 9.0, and 12.0 were equal to (2.7 ± 0.1) × 10–3, (6.2 ± 0.5) × 10–3, and (15.4 ± 0.7) × 10–3, respectively. The optimum conditions found made it possible to isolate from collagen those proteinaceous fractions that are of practical use in food industry.

The Kinetics of Hydrolysis of Animal Fat by Pancreatic Lipase

Hydrolysis of lipids from beef fat by pancreatic lipase was studied. The maximum release of free fatty acids was shown to occur at 40°C for the first 3 h of the experiment. After this, transetherification was predominant. The main kinetic parameters were the following: maximum hydrolysis rate, V = 1.25 ± 0.1 mg fat/ml min; Michaelis constant, KMH = 100 ± 12 mg fat/ml; constant of substrate inhibition, KS = 10.0 ± 0.8 mg fat/ml; equilibrium constant, KP = 277 ± 170 mg fat/ml; and activation energy of beef fat hydrolysis by pancreatic lipase, Ea = 19.1 ± 1.1 kJ/mole. The kinetic method used could be applied to development of the method for biotransformation of poorly assimilated fats into more valuable products.

Comparison of proteolytic activities of the enzyme complex from mammalian pancreas and pancreatin

The proteolytic activity and thermal stability of the enzyme complex of a cell suspension from pig and bovine pancreas glands was compared with those of pancreatin. The enzyme complex displayed the highest thermal stability and activity at 50°C. The kinetic constants, energies of activation and inactivation of the enzyme complex, and pH optimum (7.0 ± 0.1) at which this complex had the maximum proteolytic activity were determined. Pancreatin had a pH optimum of 8.0 ±0.1.

Production and purification of protein hydrolysates (review)

Recent achievements in the technology of producing protein hydrolysates are reviewed. Approaches to describing the mechanism of hydrolysis and the possibility of purifying hydrolysates for their use in the food, medical, forage, and microbiological industries are discussed.

Kinetic Characterization of Enzymatic Hydrolysis of Complex Protein Substrates for Producing Nutrient Media

Hydrolysis of a protein mixture from muscle and bone tissues with the enzymatic system from porcine pancreatic cell suspension was studied. Kinetic constants and the values of activation energy were determined for individual processes of the release of 15 amino acids. The kinetic characteristics of the overall enzymatic hydrolysis calculated from analysis of the changes in concentrations of terminal amino groups were compared with the characteristics obtained while studying the accumulation patterns of individual amino acids.

A cephalexin-synthesizing hydrolase fromXanthomonas rubrilineans

The use of peptide hydrolase (EC 3.4.13.1) fromXanthomonas rubrilineans for synthesis of the antibiotic cephalexin from 7-aminodesacetoxycephalosporanic acid was studied. The optimum conditions for production of cephalexin were determined, and the yield exceeded 80%. A method for monitoring the synthesis of this antibiotic by means of a conventional amino acid analyzer is proposed.

Isolation and Characterization of Immobilized Aminoacylase from Streptoverticillium olivoreticuli

Immobilization of aminoacylase from Streptoverticillium olivoreticuli by incorporation into acrylamide gel has been investigated. The data showed that the process should be carried out at constant pH. Thermal inactivation of the immobilized enzyme under the reaction conditions was studied. The kinetics of enzymatic stereospecific deacylation of N-acetyl-DL-phenylalanine was analyzed. The results of this study may be used in the synthesis of amino acid enantiomers.